Halfway through 1978, Triumph fitted all USA bound Bonneville 750 twins with parallel port heads and MKII carbs and, to meet EPA standards, jetted them lean. This led to poor performance compared to their UK equivalents (and earlier twins). The good news is that, with this kit, your MKII fitted 1978-1/2 onward Bonneville can run as intended! Kit includes all necessary upgrade parts to service 2 MKII carbs:
- 124/026-15 #15 pilot jet
- 124/026-35 #35 choke jet
- 2928/122-106 .106 needle jet
- 2928/060-3.5 #3-1/2 throttle slide
- 2622/124 2A1 needle
Note: you will have to remove the air jet from behind the velocity stack. It is the small aluminum disc used to restrict the flow of air through the center hole in the face of the carburetor. Removing the air jet reduces the vacuum signal on the needle/main jet leaning out the overall mixture as the slide approaches wide open operation.
If you are looking for an even better option for your parallel-port Bonneville, we sell adapters to fit mk1 concentric carbs to parallel port twins click here
For Amal MKII carb gasket kits click here
For Amal MKII cold start plungers click here